US3783818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic developing process
Assignee: Fujifilm Business Innovation Corp
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Filing: 1971-12-23
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Granted: 1974-01-08
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Expires: 1991-12-23
Abstract
Abstract An electrophotographic cascade developing process and apparatus for rendering an electrostatic latent image visible which comprises (1) providing a developing electrode in the proximity of a surface holding the electrostatic latent image to be developed thereon and in facing relationship to the surface; (2) moving the surface with respect to the electrode; (3) developing the latent image by flowing cascade developer including charged toner particles and carrier particles between the surface and the electrode while applying to the electrode a first electric potential of a polarity capable of attracting the toner particles; and (4) after the portion of the surface containing the developed image is moved past the space under the influence of the electrode, changing the first potential on the electrode to a second potential which attracts said charged toner particles less than the first potential while maintaining the flow of developer to thereby remove toner particles sticking on the electrode.
Inventors
- 👤 K Makino
- 👤 S Joh
- 👤 K Takeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:46
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0801; G03G13/00; G03G13/06; G03G13/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
189 words
Electrophotographic cascade developing apparatus for producing a predetermined number of copies of an original, said apparatus comprising a surface holding an electrostatic image of said original; a developing electrode disposed in facing relationship a predetermined spaced distance from said surface; means for moving said surface with respect to said electrode; means for flowing cascade developer including charged toner particles and carrier particles between said surface and said electrode to develop said latent image; means for applying to said electrode during said development a first potential for attracting said charged toner particles, said first potential being maintained on said electrode until said predetermined number of copies have been developed; means for detecting the passage of that portion of said surface containing the developed image away from the space under the influence of said electrode; means responsive to said detecting means for changing said first potential to a second potential which attracts said charged toner particles less than said first potential and facilitates the removal of developer particles which stick on the developing electrode; means for maintaining said flow of said developer while said second potential is applied to said electrode.
Claim 2
Dependent Claim
189 words
Electrophotographic cascade developing apparatus for producing a predetermined number of copies of an original, said apparatus comprising a surface holding an electrostatic image of said original; a developing electrode disposed in facing relationship a predetermined spaced distance from said surface; means for moving said surface with respect to said electrode; means for flowing cascade developer including charged toner particles and carrier particles between said surface and said electrode to develop said latent image; means for applying to said electrode during said development a first potential for attracting said charged toner particles, said first potential being maintained on said electrode until said predetermined number of copies have been developed; means for detecting the passage of that portion of said surface containing the developed image away from the space under the influence of said electrode; means responsive to said detecting means for changing said first potential to a second potential which attracts said charged toner particles less than said first potential and facilitates the removal of developer particles which stick on the developing electrode; means for maintaining said flow of said developer while said second potential is applied to said electrode.
Claim 3
Dependent Claim
21 words
Apparatus as in claim 1 where said potential changing means includes means for decreasing said first potential to said second potential.
Claim 4
Dependent Claim
32 words
Apparatus as in claim 1 where said potential charging means includes means for applying to said electrode said second potential which is of inverted polarity with respect to said first electric potential.
Claim 5
Dependent Claim
32 words
Apparatus as in claim 1 including means for establishing a pool of said developer in contact with said surface and above the opening into the space between said electrode and said surface.
Claim 6
Dependent Claim
38 words
Apparatus as in claim 4 where said pool establishing means includes means for establishing the length of said pool along the periphery of said surface so that said length is not less than the depth of said pool.
Claim 7
Dependent Claim
30 words
Apparatus as in claim 4 including means for replenishing the developer in said pool with the unused developer which passes through the space between said developing electrode and said surface.
References Cited (Backward Citations)
US3592675A
Cited
US3679453A
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US3649262A
Cited
US3606863A
Cited
US3601092A
Cited
US3611992A
Cited
US3611982A
Cited
US3685488A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |